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part 2″

LORD OF THE FLIES: Virtual Fruit Fly Genetics Lab, part 2

Di-Hybrid Crosses – you will be looking at 2 traits at the same time. Your goal will be to determine whether two genes are on the same chromosome or not, and how far apart they are. Before you set out to solve the problem, let’s do a warm up cross.

Warm up Cross. Cross a wild type female+/+ with a

male – design – Bristles -spineless(SS) and Body color – black(BL).

Based on your F1 results make a claim about how the black body and spineless bristles are inherited (e.g. autosomal, dominant, etc.). Justify your claim.

What are the genotypes of the F1 flies?

Using 2X2 punnett squares and the multiplication rule calculate the probability/proportions of the possible phenotypes of the F2 flies from a F1xF1 cross.

Body Color:

Bristles:

Phenotypes Probability:

+/+  _______ +/BL _________SS/+ __________    SS/BL ________

Cross the F1 female to the F1 male. And click on the Analyze tab. Check Ignore sex of Flies box only if you are certain none of the traits are sex linked. Check the box Include a test of hypothesis and fill out the expected values based on your answers above. Don’t forget to look at the total number of your flies (different each time you do a cross) in the table and use it. Make sure your expected numbers add up to the total number of flies, you can round to the nearest tenth. Record your results below.

Degrees of freedom _______________________ Chi-Square Value ______________

Look at the table and make a statement about the Null hypothesis

Next -the problem you are going to solve. Where are these genes located, different chromosomes or same chromosome. If they are on the same chromosome, how far apart are they?

Your job is to create a linkage map of the following traits, all of which are autosomal recessive

purple eye color

vestigial wing shape

spineless bristles

black body color

To do this you will need to cross a double mutant fly with a wild type fly,

then create an F2 generation from the offspring.

The F2 generation numbers will be tested using Chi-Square for the Null hypothesis – no difference from expected mendelian ratios if the genes are inherited independently.

If you reject the Null hypothesis, you will need to identify the recombinant offspring and calculate recombination frequencies, aka map distances.

Note: You must cross every trait with every other trait – this is 6 crosses in total.

But, here is the good news, you have already performed one of the crosses, your warm up cross. Simply transfer the data to the first table.

The 1st column of the table is filled out for you.

Cross #1: _____Black Body/Spineless Bristles____

P generation parents:_____________________________

F2 Generation Results:

Phenotype Ratio expected if genes are not linked Ratio expected if genes are linked Observed frequencies

(proportion column)

+, + 9/16= 0.56 +, _BL_ 3/16= 0.19 _SS_, +3/16=0.19 _BL_, _SS__ 1/16= 0.06 Are these two genes on the same chromosome? ______

If yes, what % of the offspring are recombinant? ____________

If no, support your answer with a Chi Square test

X2 = ________________________ Df = _______________________

Critical X2 value on table for p=0.05 = _________________________

Cross #2: P generation parents:_____________________________

F2 Generation Results:

Phenotype Ratio expected if genes are not linked Ratio expected if genes are linked Observed frequencies

(proportion column)

+, + +, _____ _____, + _____, _____ Are these two genes on the same chromosome? _____________

If yes, what % of the offspring are recombinant? ____________

If no, support your answer with a Chi Square test

X2 = ________________________ Df = _______________________

Critical X2 value on table for p=0.05 ______________

Cross #3: P generation parents:_____________________________

F2 Generation Results:

Phenotype Ratio expected if genes are not linked Ratio expected if genes are linked Observed frequencies

(proportion column)

+, + +, _____ _____, + _____, _____ Are these two genes on the same chromosome? _____________

If yes, what % of the offspring are recombinant? ____________

If no, support your answer with a Chi Square test

X2 = ________________________ Df = _______________________

Critical X2 value on table for p=0.05 ______________

Cross #4: P generation parents:_____________________________

F2 Generation Results:

Phenotype Ratio expected if genes are not linked Ratio expected if genes are linked Observed frequencies

(proportion column)

+, + +, _____ _____, + _____, _____ Are these two genes on the same chromosome? _____________

If yes, what % of the offspring are recombinant? ____________

If no, support your answer with a Chi Square test

X2 = ________________________ Df = _______________________

Critical X2 value on table for p=0.05 ______________

Cross #5: P generation parents:_____________________________

F2 Generation Results:

Phenotype Ratio expected if genes are not linked Ratio expected if genes are linked Observed frequencies

(proportion column)

+, + +, _____ _____, + _____, _____ Are these two genes on the same chromosome? _____________

If yes, what % of the offspring are recombinant? ____________

If no, support your answer with a Chi Square test.

X2 = ________________________ Df = _______________________

Critical X2 value on table for p=0.05 ______________

Cross #6: P generation parents:_____________________________

F2 Generation Results:

Phenotype Ratio expected if genes are not linked Ratio expected if genes are linked Observed frequencies

(proportion column)

+, + +, _____ _____, + _____, _____ Are these two genes on the same chromosome? _____________

If yes, what % of the offspring are recombinant? ____________

If no, support your answer with a Chi Square test

X2 = ________________________ Df = _______________________

Critical X2 value on table for p=0.05 ______________

Summarize your results in the table to help you construct a map of the 4 traits. Use N/A for map units if you think 2 genes are NOT on the same chromosome.

Gene/map units Bl SS VG PR

BL SS VG PR Using the table construct a map of the 4 traits. You can draw by hand and insert the image. See sample map. In the sample map 4 traits a,b,c,d are placed on 2 different chromosomes (lines). The distance between genes on the same chromosome are map units (m.u.) = recombination frequency. Note, because recombination frequencies vary and are not 100% precise, the distance between d and b and between b and c may not add up precisely to the distance between d and c, but should be adding up – approximately/roughly.

Insert your drawing here.

LORD OF THE FLIES Virtual Fruit Fly Lab Introduction

LORD OF THE FLIES: Virtual Fruit Fly Lab Introduction

Fruit flies have long since been ideal organisms to work with while studying genetics. They are easy to keep in a laboratory, have short generation times, and reproduce in large numbers. Fruit flies have 4 pairs of chromosomes, so they are reasonably simple in that regard. These model organisms were the choice of geneticists such as Thomas Hunt Morgan and Alfred Sturtevant; over the last hundred years or so we have learned a substantial amount about eukaryotic genetics from these simple organisms.

In this virtual lab, you will work with several different fly characteristics to, first, replicate the famous experiments of Thomas Hunt Morgan and Alfred Sturtevant. Then, you will determine the inheritance patterns of three other traits by designing and executing your own experiments. You will use a Chi-square Analysis to analyze your data and justify your conclusions.

https://www.sciencecourseware.org/FlyLabJS/

The main screen of the simulation shows how you, the scientist, can design the flies you’d like to cross.

To familiarize yourself with fly terminology, you will examine each design option one at a time. But first, it’s important students understand the definition of “wild-type,” which is an option for each characteristic aside from sex. “Wild-type” is the most common phenotypic expression in nature. So, if you were to catch a fruit fly buzzing about your house, it’s most likely going to be wild-type for all characteristics. Wild-type characteristics are represented with a ‘+’ sign. It’s important to note, though, that wild-type does not necessarily mean that a particular allele is dominant or recessive: it’s the non-mutated, most common version of the characteristic.

The simulation will default to wild-type for each trait unless you choose something else. To choose something else, click the tiny circle to the left of the phenotype you are selecting. To return all characteristics to wild-type, click “reset all” at the bottom.

Click on each of the tabs on the left to explore the different phenotypes for each characteristic.

Let’s practice using some crosses. We will start mono-hybrid crosses, following one trait. For each cross you will examine the F1 generation to determine which allele is dominant and which is recessive, wild type or mutant. You will then mate a female F1 to a male F1 and examine the F2 generation.

The instructions for mating are detailed only for the 1st cross. Follow the steps for other crosses.

Cross # 1

In the simulation, “select fly for mating” a female fly that is wild-type for all characteristics.

Then, under the grayed male fly, click “design fly.” The designer will default to male.

Then, under “wing size” select “vestigial” and then “select fly for mating”.

Double check you’ve not selected something silly (the top should look like this) and then click “Mate Flies”

and then click “Mate Flies”

Your screen will immediately show the results of your cross. NOTE that there are some random processes at play here, so your specific values will not be identical to mine. Here are the results:

Based on YOUR results (not mine) predict which allele is the recessive allele. Justify your prediction.

Based on the answer to question 1, what are the expected ratios for wild type vs. vestigial wing size in the F2 generation. Use a punnett square if you need to.

Experimental Design Review:

In this lab what is your independent variable (what are your changing)?

In this lab what is your dependent variable (what are you measuring as a result of your change)?

To then produce the F2 generation,

1. “Select to Mate” both the male and female,

2. then click “Mate Flies.”

It should give results similar to these (again: slight variations for randomness):

Do the results of your F2 generation support your expected ratios from question #2?

Now, you want to check whether the results obtained “match” your expected results. The simulation has a built-in Chi-Square helper (yay!) but you will still need to do some independent thinking (also yay!). Click on the “Analyze” tab and then check the box toward the top to “Include a test of hypothesis.” If the number of female and male flies with a given phenotype are roughly the same, check the box “Ignore sex of flies” . We will explore this feature later.

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To test the Null hypothesis, you will need to fill out the table that appears with the expected numbers. Using the predicted ratios from above, multiply the total number of flies in the cross. Note this number will be different each time you perform a cross, and different than mine. E.g. if you expected 1:1 ration, you would multiply 1076 by ½ to get the expected # of flies with a given phenotype.48672751201675

On the table it produces, the Chi-squared test statistic is calculated for you, the degrees of freedom are determined, and the level of significance (AKA p-value) is given. Now, before you get all giddy, keep in mind that you will be required to do this sort of analysis on the AP exam using only your calculator and formula sheet, so best make sure you understand what’s going on here before you turn your brain off.

For this reason, you will use the Chi-square value from the table and the degrees of freedom and compare it to the Critical value table below (taken from the Formula sheet you will get on the AP exam) to determine whether you reject or fail to reject the Null.

Make a statement about the Null Hypothesis for Cross #1 (everything you have done with breeding flies so far) and justify it with a comparison between the calculated Chi-Square value and the Critical value for the appropriate degree of freedom.

Cross #2 – Starting with a new set of flies. Mate a wild type female with a male who’s wing size – apterous

Based on your results predict which allele is the recessive allele. Justify your prediction.

Based on the answer to question 5, what are the expected ratios for wild type vs. apterous in the F2 generation. Use a punnett square if you need to.

Make statement about the Null Hypothesis for Cross #2 and justify it with a comparison between the calculated Chi-Square value and the Critical value for the appropriate degree of freedom.

Let’s make it interesting with Cross # 3.

Starting with a new set of flies. Mate a wild type female with a male with white eye color.

Based on your results predict which allele is the recessive allele. Justify your prediction.

Based on the answer to question 8, what are the expected ratios for wild type vs. white eyes in the F2 generation. Use a punnett square if you need to.

Cross the F1 flies to obtain your F2 generation. Paste an image of the results here. What do you notice?

Can you offer a possible explanation of your results?

Write out the genotype of the F1 parents (based on your hypothesis from #8). What cross(es) can you perform with the F1 flies (other than to each other) that would help confirm the genotypes?

You just performed the original Thomas Morgan cross, the one that led to the discovery of gene linkage.

Lords

Lords

Student’s Name

Instructor’s Name

Institution Affiliation

Date

It is correct to say that lords were the most important people in Europe in the 1100s, 1200s and 1300s because as political and economic leaders, they were not considered to be performing two different professions at the same time. It was not only money and labor that the lords were able to extract from their peasants; they also had access to a huge variety of other resources. Additionally, they were judges, protectors, and chiefs, to whom people who “held” their land from them or lived on their grounds were tied, separate from any more binding and personal relationships, by a very wide but very genuine responsibility to assist and obey.

However, the Lords were more than a collection of wealthy men’s enterprises; they were a political organization. The chiefs’ authority was not restricted to their “business premises,” as it is in capitalist firms; rather, they had an influence on the people’s whole lives and functioned alongside or even in place of the state and the family’s authority. They had their own law, which was as a rule customary and determined the relationship between subjects and lords, as well as the precise demographic restrictions within which these conventional standards were enforced.

The Lords developed a system called Manorial system, which included compulsory labor and the right for subjects who were occupants on the land to cultivate a portion of their land. In return, they are given land that they may cultivate for themselves. of their land devoted to the lord of feudalism. As well as financial obligations, It was required to bill participants for a number of services, such as road construction and maintenance at specific seasons of the year. When they had finished with all of their hard work, they were able to finally settle down on their own plots of land and enjoy their newfound freedom. Their own self-interest in completing the Lord’s land as fast as possible before returning to work on their own property necessitated the need for oversight and control of their activities.

The Lords provided security for the subjects in that, It was their responsibility to administer and defend the land in order to safeguard it and the people who lived and worked on it. The lords had employed officials in order to guarantee that the villagers were carrying out their responsibilities. Lords also functioned as judges in manor courts, and they had the ability to condemn and punish anyone who defied the laws of their respective counties. In the king’s administration, certain of the king’s lords held important posts. It was common for lords of high rank to fight on their own behalf, or at the very least furnish their superiors with an army of well-trained combatants, during times of strife.

Looking into a New Piece of Technology

Looking into a New Piece of Technology

The only thing that is constant in business, as well as in life, is change. A large number of businesses throughout the world are presently undertaking digital transformation – that is, replacing outdated systems with new digital technologies and transferring their IT assets and infrastructure to cloud-based services. Firms, on the other hand, may find it scary to implement new technology because of the costs involved, the logistical issues connected with the shift, the necessary employee training, and the fear of the unknown. While such concerns are understandable, digital transformation is now a need for any businesses seeking to remain competitive (Humphreys & Wilken, 2015). In the minds of many, it’s now or never: the time has come to embrace change and catapult your company into the twenty-first century.

Nowadays, it’s impossible to imagine doing business without the use of the Internet. Nevertheless, if you go back a few years, you’ll be shocked at how many digital skeptics are still alive and well. We are seeing a significant shift in how we connect with consumers, sell products and services, communicate with employees, and, in a nutshell, do business as a result of social media platforms such as Facebook, Twitter, Instagram, LinkedIn, and others. The digital transformation that began with the web has now spread to social media platforms (Zhu & Chen, 2015). Furthermore, it has a significant impact on the bottom line. In my opinion, the most effective approach for businesses to remain successful today is to embrace social media to its fullest extent. If you’re looking backwards, you’re blinkered, and, most all, you’re putting your company at risk. Failing to include Twitter, Facebook, and other social networks into your strategy in 2015 is roughly equivalent to claiming that the internet was only a fad a decade or so ago.

Firms benefit from open communication allowed by social media because it allows them to better understand their clients’ requirements and encourages them to respond to those needs in a proactive and effective manner. To be productive and have an impact on organizational performance, any technology must be adopted properly by enterprises. With the increasing popularity and adoption of social media, there has been an increase in interest in the factors that contribute to the efficient integration of social media into companies. While previous study has looked at technology adoption in a variety of contexts and discovered a number of factors that impact how people use technology, social media is unlike any other information technology innovation or Internet-based system in that it is completely new. Social media is a more open and public-oriented system, which has a variety of advantages and disadvantages (Baird & Parasnis, 2011). However, it is unclear to what degree social media might benefit businesses in the long run. This led to an investigation of the technological, organizational, and environmental factors that may impact the adoption of social media in corporations, as well as the benefits of social media adoption in corporations, by the authors of this paper.

When deciding whether to adopt new social media platforms, organizations should take into account the characteristics of current technologies and industry competition. They should also communicate the importance of effective organizational use of social media in terms of improved business performance early and frequently to all levels of employees, and demonstrate the benefit of organizational social media usage by clearly communicating the specific cost savings, improved information and relationship management, and improved customer service (Yan, 2011). It is vital for a company’s success to establish relationships with consumers through social media platforms and to manage these channels properly. It is possible that social media will have a positive influence on sales as well as brand loyalty and connection to a significant level. Although social media platforms were primarily intended for personal use and participation, their growth and increasing popularity have converted them into a powerful tool for developing brand communities and promoting products and services. The use of social media in the delivery of customer service is strongly dependant on it (Jones, Borgman, & Ulusoy, 2015). The combined benefits of easy brand accessibility through social media platforms such as Twitter, Facebook, YouTube, and other similar platforms allow for instant customer interaction and engaging social engagement, while also supporting brand expansion and extensive communication over a variety of channels.

It saves enterprises a significant amount of time and money. Furthermore, by leveraging social networking sites, you may be able to reach a far wider audience than you would be able to reach through more traditional methods. It is especially convenient for consumers because it makes use of their social network and free time; it also allows for more rapid connection with the customer service department, hence minimizing the need for a large number of unwelcome phone calls (Chatzigeorgiou, 2017). It is beneficial for a business to employ many social media sites at the same time in order to present clients with a variety of contact options.

Three-quarters of internet-connected individuals in the United States presently use social networking sites, according to a study conducted by the Pew Internet Project. In fact, if we restrict our conversation to millennials and young people — in other words, tomorrow’s customers — that percentage rises significantly. The amount to which people utilize social media, on the other hand, is more telling: According to GlobalWebIndex, the average user signs in for around 1.7 hours per day, or 12 hours per week, on their computer (Iankova et al., 2019). Millennials, according to some estimates, spend more time on YouTube than they do watching television (Appel et al., 2020). Approximately 1.4 billion monthly active users from across the world log on to the network on a daily basis, 365 days a year, for an average of more than 20 minutes. It shouldn’t come as a surprise that social media is presently driving more website traffic than traditional search engines.

In a technology-driven world, more companies are using brochures. Brochures send the subtle message that your business is professional, reliable, and committed to quality. If you’re considering using brochures in your marketing plan, take notice of the following benefits as well. You can strategically place brochures in a wide variety of locations. This allows your company to relay positive and accurate information to more people and attract new customers. It’s easy to place brochures in promotional giveaways you send through the mail or on tables in your office. Compared with some online marketing options, brochures are a low-cost marketing plan. Plus, most professional print shops will work with you to design and produce sleek brochures that fit your budget. Brochures also decrease in price if you buy in bulk. Many companies who use mail advertising or participate in trade shows buy brochures in bulk. Once you have the eyes of your potential clients reading your brochure, you can build trust. Most companies include their objectives and goals in their brochure. This information helps clients see the caring and devoted side of your company. When clients can read about how you care, they trust your company more.

Brochures provide company owners with the ability to condense a large amount of information into a small amount of space. Even a trifold design has space on the flaps for you to describe your services and products in greater detail. Aside from that, brochures include far more information than other forms of printing, such as postcards or letters. Whether you want to include product prices or tell the story of your company, you have plenty of space to communicate your whole message. You may even be able to generate immediate cash by including coupons or discounts in your brochure. The majority of the time, professional presenters communicate directly to a single person among a large audience. This method enables the speaker to interact with the audience on a more personal level, which is often more effective than speaking to a big group of people in a formal setting. In a similar vein, you might use the same technique in your brochure. When a potential customer reads your brochure, you have the opportunity to engage in that one-on-one dialogue with them. In your brochures, make sure to explain why your customers need your product or service in a clear and concise manner. The printed sales material of a well-established company connects with the company’s clients. While business cards and letterheads help to create credibility, a brochure communicates your dedication to your customers and prospects. The general public expects printed materials to come from a credible source.

Brochures, in general, are characterized by their small size, both in terms of physical size and in terms of information. They are able to fit a great deal of information into their little frame. Generally speaking, brochures are capable of presenting a company, offering an overview of products and/or services, highlighting features and advantages, and providing contact information. They are, in essence, a condensed version of what a website may offer. In addition, when done properly, a brochure provides the buyer with a clear idea of your company and the products and services you have to offer simply by reading your brochure. brochures are more versatile than other types of print media in that they can be mailed, used on-site, and distributed at events. Because of their multi-purpose properties, printing a larger quantity of brochures is a clear option because you know they will be beneficial in a variety of scenarios in the future.

References

Appel, G., Grewal, L., Hadi, R., & Stephen, A. T. (2020). The future of social media in marketing. Journal of the Academy of Marketing Science, 48(1), 79-95.

Baird, C. H., & Parasnis, G. (2011). From social media to social customer relationship management. Strategy & leadership.

Chatzigeorgiou, C. (2017). Modelling the impact of social media influencers on behavioural intentions of millennials: The case of tourism in rural areas in Greece. Journal of Tourism, Heritage & Services Marketing (JTHSM), 3(2), 25-29.

Humphreys, L., & Wilken, R. (2015). Social media, small businesses, and the control of information. Information, Communication & Society, 18(3), 295-309.

Iankova, S., Davies, I., Archer-Brown, C., Marder, B., & Yau, A. (2019). A comparison of social media marketing between B2B, B2C and mixed business models. Industrial Marketing Management, 81, 169-179.

Jones, N., Borgman, R., & Ulusoy, E. (2015). Impact of social media on small businesses. Journal of Small Business and Enterprise Development.

Yan, J. (2011). Social media in branding: Fulfilling a need. Journal of brand management, 18(9), 688-696.

Zhu, Y. Q., & Chen, H. G. (2015). Social media and human need satisfaction: Implications for social media marketing. Business horizons, 58(3), 335-345.

on the other hand

is the face of savagery. They have divergent ideas concerning ways to rule the island. Ralph represents order and democracy

survival

and civilization. In support of using fire Ralph says “We can help them find us. A ship near the island may not notice us but will notice smoke on top of a mountain. We must make fire” (Golding

but they lie between Jack and Ralph. Initially

many boys have high levels of civilization and that is the reason they vote for Ralph. As the novel progresses

William. Lord of the Flies. London: Faber & Faber

1954

part 2″

LORD OF THE FLIES: Virtual Fruit Fly Genetics Lab, part 2

Di-Hybrid Crosses – you will be looking at 2 traits at the same time. Your goal will be to determine whether two genes are on the same chromosome or not, and how far apart they are. Before you set out to solve the problem, let’s do a warm up cross.

Warm up Cross. Cross a wild type female+/+ with a

male – design – Bristles -spineless(SS) and Body color – black(BL).

Based on your F1 results make a claim about how the black body and spineless bristles are inherited (e.g. autosomal, dominant, etc.). Justify your claim.

What are the genotypes of the F1 flies?

Using 2X2 punnett squares and the multiplication rule calculate the probability/proportions of the possible phenotypes of the F2 flies from a F1xF1 cross.

Body Color:

Bristles:

Phenotypes Probability:

+/+  _______ +/BL _________SS/+ __________    SS/BL ________

Cross the F1 female to the F1 male. And click on the Analyze tab. Check Ignore sex of Flies box only if you are certain none of the traits are sex linked. Check the box Include a test of hypothesis and fill out the expected values based on your answers above. Don’t forget to look at the total number of your flies (different each time you do a cross) in the table and use it. Make sure your expected numbers add up to the total number of flies, you can round to the nearest tenth. Record your results below.

Degrees of freedom _______________________ Chi-Square Value ______________

Look at the table and make a statement about the Null hypothesis

Next -the problem you are going to solve. Where are these genes located, different chromosomes or same chromosome. If they are on the same chromosome, how far apart are they?

Your job is to create a linkage map of the following traits, all of which are autosomal recessive

purple eye color

vestigial wing shape

spineless bristles

black body color

To do this you will need to cross a double mutant fly with a wild type fly,

then create an F2 generation from the offspring.

The F2 generation numbers will be tested using Chi-Square for the Null hypothesis – no difference from expected mendelian ratios if the genes are inherited independently.

If you reject the Null hypothesis, you will need to identify the recombinant offspring and calculate recombination frequencies, aka map distances.

Note: You must cross every trait with every other trait – this is 6 crosses in total.

But, here is the good news, you have already performed one of the crosses, your warm up cross. Simply transfer the data to the first table.

The 1st column of the table is filled out for you.

Cross #1: _____Black Body/Spineless Bristles____

P generation parents:_____________________________

F2 Generation Results:

Phenotype Ratio expected if genes are not linked Ratio expected if genes are linked Observed frequencies

(proportion column)

+, + 9/16= 0.56 +, _BL_ 3/16= 0.19 _SS_, +3/16=0.19 _BL_, _SS__ 1/16= 0.06 Are these two genes on the same chromosome? ______

If yes, what % of the offspring are recombinant? ____________

If no, support your answer with a Chi Square test

X2 = ________________________ Df = _______________________

Critical X2 value on table for p=0.05 = _________________________

Cross #2: P generation parents:_____________________________

F2 Generation Results:

Phenotype Ratio expected if genes are not linked Ratio expected if genes are linked Observed frequencies

(proportion column)

+, + +, _____ _____, + _____, _____ Are these two genes on the same chromosome? _____________

If yes, what % of the offspring are recombinant? ____________

If no, support your answer with a Chi Square test

X2 = ________________________ Df = _______________________

Critical X2 value on table for p=0.05 ______________

Cross #3: P generation parents:_____________________________

F2 Generation Results:

Phenotype Ratio expected if genes are not linked Ratio expected if genes are linked Observed frequencies

(proportion column)

+, + +, _____ _____, + _____, _____ Are these two genes on the same chromosome? _____________

If yes, what % of the offspring are recombinant? ____________

If no, support your answer with a Chi Square test

X2 = ________________________ Df = _______________________

Critical X2 value on table for p=0.05 ______________

Cross #4: P generation parents:_____________________________

F2 Generation Results:

Phenotype Ratio expected if genes are not linked Ratio expected if genes are linked Observed frequencies

(proportion column)

+, + +, _____ _____, + _____, _____ Are these two genes on the same chromosome? _____________

If yes, what % of the offspring are recombinant? ____________

If no, support your answer with a Chi Square test

X2 = ________________________ Df = _______________________

Critical X2 value on table for p=0.05 ______________

Cross #5: P generation parents:_____________________________

F2 Generation Results:

Phenotype Ratio expected if genes are not linked Ratio expected if genes are linked Observed frequencies

(proportion column)

+, + +, _____ _____, + _____, _____ Are these two genes on the same chromosome? _____________

If yes, what % of the offspring are recombinant? ____________

If no, support your answer with a Chi Square test.

X2 = ________________________ Df = _______________________

Critical X2 value on table for p=0.05 ______________

Cross #6: P generation parents:_____________________________

F2 Generation Results:

Phenotype Ratio expected if genes are not linked Ratio expected if genes are linked Observed frequencies

(proportion column)

+, + +, _____ _____, + _____, _____ Are these two genes on the same chromosome? _____________

If yes, what % of the offspring are recombinant? ____________

If no, support your answer with a Chi Square test

X2 = ________________________ Df = _______________________

Critical X2 value on table for p=0.05 ______________

Summarize your results in the table to help you construct a map of the 4 traits. Use N/A for map units if you think 2 genes are NOT on the same chromosome.

Gene/map units Bl SS VG PR

BL SS VG PR Using the table construct a map of the 4 traits. You can draw by hand and insert the image. See sample map. In the sample map 4 traits a,b,c,d are placed on 2 different chromosomes (lines). The distance between genes on the same chromosome are map units (m.u.) = recombination frequency. Note, because recombination frequencies vary and are not 100% precise, the distance between d and b and between b and c may not add up precisely to the distance between d and c, but should be adding up – approximately/roughly.

Insert your drawing here.

LORD OF THE FLIES Virtual Fruit Fly Lab Introduction

LORD OF THE FLIES: Virtual Fruit Fly Lab Introduction

Fruit flies have long since been ideal organisms to work with while studying genetics. They are easy to keep in a laboratory, have short generation times, and reproduce in large numbers. Fruit flies have 4 pairs of chromosomes, so they are reasonably simple in that regard. These model organisms were the choice of geneticists such as Thomas Hunt Morgan and Alfred Sturtevant; over the last hundred years or so we have learned a substantial amount about eukaryotic genetics from these simple organisms.

In this virtual lab, you will work with several different fly characteristics to, first, replicate the famous experiments of Thomas Hunt Morgan and Alfred Sturtevant. Then, you will determine the inheritance patterns of three other traits by designing and executing your own experiments. You will use a Chi-square Analysis to analyze your data and justify your conclusions.

https://www.sciencecourseware.org/FlyLabJS/

The main screen of the simulation shows how you, the scientist, can design the flies you’d like to cross.

To familiarize yourself with fly terminology, you will examine each design option one at a time. But first, it’s important students understand the definition of “wild-type,” which is an option for each characteristic aside from sex. “Wild-type” is the most common phenotypic expression in nature. So, if you were to catch a fruit fly buzzing about your house, it’s most likely going to be wild-type for all characteristics. Wild-type characteristics are represented with a ‘+’ sign. It’s important to note, though, that wild-type does not necessarily mean that a particular allele is dominant or recessive: it’s the non-mutated, most common version of the characteristic.

The simulation will default to wild-type for each trait unless you choose something else. To choose something else, click the tiny circle to the left of the phenotype you are selecting. To return all characteristics to wild-type, click “reset all” at the bottom.

Click on each of the tabs on the left to explore the different phenotypes for each characteristic.

Let’s practice using some crosses. We will start mono-hybrid crosses, following one trait. For each cross you will examine the F1 generation to determine which allele is dominant and which is recessive, wild type or mutant. You will then mate a female F1 to a male F1 and examine the F2 generation.

The instructions for mating are detailed only for the 1st cross. Follow the steps for other crosses.

Cross # 1

In the simulation, “select fly for mating” a female fly that is wild-type for all characteristics.

Then, under the grayed male fly, click “design fly.” The designer will default to male.

Then, under “wing size” select “vestigial” and then “select fly for mating”.

Double check you’ve not selected something silly (the top should look like this) and then click “Mate Flies”

and then click “Mate Flies”

Your screen will immediately show the results of your cross. NOTE that there are some random processes at play here, so your specific values will not be identical to mine. Here are the results:

Based on YOUR results (not mine) predict which allele is the recessive allele. Justify your prediction.

Based on the answer to question 1, what are the expected ratios for wild type vs. vestigial wing size in the F2 generation. Use a punnett square if you need to.

Experimental Design Review:

In this lab what is your independent variable (what are your changing)?

In this lab what is your dependent variable (what are you measuring as a result of your change)?

To then produce the F2 generation,

1. “Select to Mate” both the male and female,

2. then click “Mate Flies.”

It should give results similar to these (again: slight variations for randomness):

Do the results of your F2 generation support your expected ratios from question #2?

Now, you want to check whether the results obtained “match” your expected results. The simulation has a built-in Chi-Square helper (yay!) but you will still need to do some independent thinking (also yay!). Click on the “Analyze” tab and then check the box toward the top to “Include a test of hypothesis.” If the number of female and male flies with a given phenotype are roughly the same, check the box “Ignore sex of flies” . We will explore this feature later.

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To test the Null hypothesis, you will need to fill out the table that appears with the expected numbers. Using the predicted ratios from above, multiply the total number of flies in the cross. Note this number will be different each time you perform a cross, and different than mine. E.g. if you expected 1:1 ration, you would multiply 1076 by ½ to get the expected # of flies with a given phenotype.48672751201675

On the table it produces, the Chi-squared test statistic is calculated for you, the degrees of freedom are determined, and the level of significance (AKA p-value) is given. Now, before you get all giddy, keep in mind that you will be required to do this sort of analysis on the AP exam using only your calculator and formula sheet, so best make sure you understand what’s going on here before you turn your brain off.

For this reason, you will use the Chi-square value from the table and the degrees of freedom and compare it to the Critical value table below (taken from the Formula sheet you will get on the AP exam) to determine whether you reject or fail to reject the Null.

Make a statement about the Null Hypothesis for Cross #1 (everything you have done with breeding flies so far) and justify it with a comparison between the calculated Chi-Square value and the Critical value for the appropriate degree of freedom.

Cross #2 – Starting with a new set of flies. Mate a wild type female with a male who’s wing size – apterous

Based on your results predict which allele is the recessive allele. Justify your prediction.

Based on the answer to question 5, what are the expected ratios for wild type vs. apterous in the F2 generation. Use a punnett square if you need to.

Make statement about the Null Hypothesis for Cross #2 and justify it with a comparison between the calculated Chi-Square value and the Critical value for the appropriate degree of freedom.

Let’s make it interesting with Cross # 3.

Starting with a new set of flies. Mate a wild type female with a male with white eye color.

Based on your results predict which allele is the recessive allele. Justify your prediction.

Based on the answer to question 8, what are the expected ratios for wild type vs. white eyes in the F2 generation. Use a punnett square if you need to.

Cross the F1 flies to obtain your F2 generation. Paste an image of the results here. What do you notice?

Can you offer a possible explanation of your results?

Write out the genotype of the F1 parents (based on your hypothesis from #8). What cross(es) can you perform with the F1 flies (other than to each other) that would help confirm the genotypes?

You just performed the original Thomas Morgan cross, the one that led to the discovery of gene linkage.